re: Maybe not.
In recent surveys, most Americans overwhelmingly oppose same sex marriage, but oppose by a narrow margin a constitutional amendment on this subject.
The latter probably has more to do with how people feel about the constitution and the appropriateness of an amendment for this circumstance than they do about gay marriage.
In other words, there isn't the massive movement for gay marriage that you might think, nor will there be the massive backlash against Bush (other than by the Left and its media buttmonkeys) that you might hope for.